1. Field
The embodiments relate to an organic light emitting display apparatus.
2. Description of the Related Art
In general, an organic light emitting display apparatus displays colors by emitting light when holes and electrons that are injected from an anode and a cathode are recombined in an emission layer. The organic light emitting display has a stacked structure in which an emission layer is inserted between a pixel electrode that is an anode and a counter electrode that is a cathode.
A unit pixel of an organic light emitting display apparatus includes red, green, and blue sub pixels which are combined to display a desired color. In more detail, each sub pixel has a structure in which an emission layer for emitting red, green, or blue light is disposed between two electrodes, and a unit pixel displays a color by appropriately combining the red, green, and blue light.
Meanwhile, currently, in many cases, sub pixels are formed in a resonance structure in order to increase light extraction efficiency of an organic light emitting display apparatus. That is, the resonance structure induces constructive interference of light between two electrodes by forming one of an anode and a cathode for displaying an image as a translucent electrode, and forming the other as a total reflection electrode, and thus a quite enhanced light may be extracted from each sub pixel.
However, if a strong resonance structure is used, although light extraction efficiency is increased, viewing angle characteristics may deteriorate. For example, if a strong resonance structure is used, a significant brightness reduction and color shift may occur, according to a viewing angle.
Accordingly, in order to implement a product having high reliability, a new structure capable of improving light extraction efficiency and satisfactorily maintaining viewing angle characteristics is required.